1. Field of the Invention
The present invention relates to a power allocating apparatus, and more particularly, to a power allocating apparatus that allocates power of a plurality of power supply modules.
2. Description of the Prior Art
Energy saving is a prescient topic. To conserve energy, all electronic equipments have respective standard power conversion rates according to the regulations given by the U.S. environment protection agency (EPA). For example, the power conversion rate of the power supply of a personal computer sold in the U.S. has to be higher than 80 percent. In a conventional computer system, the configuration of a switching power supply includes a main power supply and an auxiliary power supply as shown in FIG. 1. FIG. 1 is a diagram illustrating the configuration of a conventional switching power supply 100. The conventional switching power supply 100 comprises a main power device 102 and an auxiliary power device 104, wherein the main power device 102 is utilized for providing a first current Io1 and a first voltage Vo1 for a main power load 106, and the auxiliary power device 104 is utilized for providing a second current Io2 and a second voltage Vo2 for an auxiliary power load 108. When the computer system is under a normal operation mode, the main power device 102 provides the first current Io1 and the first voltage Vo1 to the main power load 106, while the auxiliary power device 104 provides the second current Io2 and the second voltage Vo2 to the auxiliary power load 108; when the computer is under a sleep mode, the main power device 102 does not provide the first current lo, and the first voltage Vo1 to the main power load 106, while the auxiliary power device 104 continues to provide the second current Io2 and the second voltage Vo2 to the auxiliary power load 108 to maintain the basic operation of the computer system. In other words, the auxiliary power device 104 is always on. However, in comparison with the output power of the main power device 102, the auxiliary power device 104 has a relatively low output power (i.e., the second current Io2 and the second voltage Vo2). For example, the output power of the auxiliary power device 104 may only be 10-20 W (watt). Therefore, for the purpose of saving costs, the conventional auxiliary power device 104 is always implemented by a power supply having a relatively low power conversion rate. For example, when the conventional auxiliary power device 104 operates under a heavy load, the power conversion rate is merely 78 percent. Since the main power consumed by the power system is provided by the main power device 102, the conventional main power device 102 is implemented by the power supply having a relatively high power conversion rate. Furthermore, when the conventional computer system operates under the normal operation mode, the main power device 102 and the auxiliary power device 104 provide power to, respectively, the main power load 106 and the auxiliary power load 108 at the same time, therefore the entire power conversion rate of the switching power supply may be affected by the auxiliary power device 104 having the relatively low power conversion rate. In other words, the entire power conversion rate of the switching power supply may be decreased as a result of the low power conversion rate of the auxiliary power device 104. Consequently, the power conversion rate of the conventional switching power supply may not conform to the specifications regulated by the EPA under the normal operation mode (higher than 80 percent). Therefore, to increase the power conversion rate of the power supply device of the computer is an urgent problem in the field of power supply.